DMfreeⓇ(Green Tea Extract) Inhibits IL-6 of Mycobacterium leprae Infected Mesenchymal Stem Cells
Previous reports revealed that DMfree (green tea extract) inhibited expression of the IL-6 gene in Mycobacterium lepraeinfected MSCs (mesenchymal stem cells). This study aimed to measure IL-6, IL-1β, TNF-α and PGE2 production in M. leprae-infected MSCs using ELISA. To confirm the effect of DMfree on IL-6 and signal transduction, a western blotting test was performed. DMfree inhibited the expression of IL-6 in the MSCs and the heterodimer of STAT3, which also affects the expression of multiple genes. Though DMfree pre-treatment of control MSCs produced a baseline level of IL-6, it significantly inhibited the production of IL-6 in M. leprae-infected MSCs. There was no significant difference in IL-6 production between 1 and 7 day treatment groups. M. leprae-infected MSCs produced more IL-1β, TNF-α and PGE2, but DMfree could not inhibit their production at a physiological concentration. This is different from other reports that used higher concentration of EGCG treatment, resulting in significant inhibition of the cytokines. The inhibition appears to be related to the concentration of EGCG. These results indicate that DMfree can alleviate inflammation involving IL-6.